Elsevier Health Journal
Alan B. MacDonald
St. Catherine of Siena Medical Center, Department of Pathology, 50 Rte 25 A, Smithtown, NY 11787, USA
Received 20 February 2006; accepted 23 February 2006
Summary Here is hypothesized a truly revolutionary notion that rounded cystic forms of Borrelia burgdorferi are the
root cause of the rounded structures called plaques in the Alzheimer brain. Rounded ‘‘plaques’ in high density in brain
tissue are emblematic of Alzheimer’s disease (AD). Plaques may be conceptualized as rounded ‘‘pock mark-like’’ areas
of brain tissue injury. In this century, in brain tissue of AD, plaques are Amyloid Plaques according to the most up to date
textbooks. In the last century, however, Dr. Alois Alzheimer did not require amyloid as the pathogenesis for either the
disease or for the origin of its plaques. Surely, amyloid is an event in AD, but it may not be the primal cause of AD. Indeed
in plaques, amyloid is regularly represented by the ‘‘congophilic core’’ structure which is so named because the waxy
amyloid material binds the congo red stain and is congophilic. However an accepted subset of plaques in AD is devoid of a
congophilic amyloid core region (these plaques ‘‘cotton wool’’ type plaques, lack a central congophilic core structure).
Furthermore, there is ‘‘plaque diversity’’ in Alzheimer’s; small, medium and large plaques parallel variable cystic
diameters for Borrelia burgdorferi. Perturbations of AD plaque structure (i.e. young plaques devoid of a central core
and older plaques with or without a central core structure) offer room for an alternate pathway for explanation of
ontogeny of the plaque structures. If amyloid is not required to initiate all of the possible plaques in Alzheimer’s, is it
possible that amyloid just a by product of a more fundamental primal path to dementia? If a byproduct status is assigned
to amyloid in the realm of plaque formation, then is amyloid also an epiphenomenon rather than a primary pathogenesis
for Alzheimer’s disease. In the ‘‘anatomy is destiny’’ model, cysts of borrelia are always round. Why then not accept
roundness as a fundamental ‘‘structure determines function’’ argument for the answer to the mystery of why Alzheimer
plaques are always round? Parataxis causality, a concept borrowed from philosophy, is the error that comes from linking
two events, which occur contemporaneously or in close proximity to one another with a cause and effect relationship.
Parataxis tells us that what appears to be cause and effect in the couplet ‘‘amyloid plaque’’ merely by a proximity
relationship may be ‘‘spurious causality’’ which is a cognitive dead end.